66189078 has 96 divisors (see below), whose sum is σ = 160056000. Its totient is φ = 19692288.

The previous prime is 66189059. The next prime is 66189089. The reversal of 66189078 is 87098166.

It is a happy number.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 444148 + ... + 444296.

It is an arithmetic number, because the mean of its divisors is an integer number (1667250).

Almost surely, 2^66189078 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66189078, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80028000).

66189078 is an abundant number, since it is smaller than the sum of its proper divisors (93866922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66189078 is a wasteful number, since it uses less digits than its factorization.

66189078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 66189078 is about 8135.6670285847. The cubic root of 66189078 is about 404.5095480528.

The spelling of 66189078 in words is "sixty-six million, one hundred eighty-nine thousand, seventy-eight".